Protein Pipeline: Reagents for Structure-Based Detection

The ability to respond adequately to a biological threat requires not only rapid and accurate detection, but also a detailed understanding of the threat agent to determine the appropriate response actions. The objective of this work had been to monitor real-time expression of virulence factors to gain a better mechanistic understanding of plague. Specifically, we have utilized mass spectrometry-based proteomics approaches to identify differential protein expression in Yersinia pestis as a function of virulence by mimicking temperature and calcium concentrations of host and flea vector thus providing protein detection biomarkers for plague and define novel virulence factors.

One challenge in reagent development for pathogen detection is targeting reagents against biomarkers that are actually expressed with in the organism. While not as important for DNA based detection, this challenge is far more critical for protein-based detection as not all proteins predicted to be coded from a genome are expressed under a specific condition. Without validation or protein expression, the risk exists that reagents would be targeted against proteins that are not actually present, thus wasting both time and resources. To this end, this portion of the project has provided validated biomarkers for Y. pestis that are isolated against proteins actually expressed in the pathogen under conditions closely resembling those in which the organisms are to be detected.